There’s not enough green in the city’s budget to fund New York’s biggest park projects, the Post has learned.

Only two years ago, Mayor Bloomberg was hailed as a city green space champion after announcing a $386 million plan with fancy renderings to redo eight downtrodden parks through his sweeping PlaNYC initiative.

But with the city in fiscal crisis, the mayor’s new spending plan cuts funding in half for five of them.

Projects to revive Manhattan’s Fort Washington Park, Dreier-Offerman Park in Brooklyn, Soundview Park in the Bronx and Highland and Rockaway parks in Queens have been gutted from a combined $206 million in 2007 to $102.9 million, city documents show.

At Dreier-Offerman near Coney Island, a $40 million plan to reclaim the park from the homeless and junkies by adding new athletic fields and restoring wetlands was cut to $19 million.

Fort Washington Park in Washington Heights saw a similar $40 million project slashed to $21.5 million while a $50 million plan to restore Ridgewood Reservoir and bring new athletic fields to Highland Park fell to $19.8 million.

In fact, the Parks Department’s five-year capital plan for projects through fiscal 2013 was cut by $338 million — or 14 percent — compared to mayor’s preliminary budget in January, the city’s Independent Budget Office says.

And the city is in danger of becoming even less green.

The revised $2.3 billion capital plan, part of the executive budget the City Council will vote on next month, sets aside $456.2 million for projects for the fiscal year starting July 1. But a May 19 City Council study predicts “it is unlikely that without significant staff increases, the Parks Department will be able to complete anywhere near [its] goal.”

A Parks official speaking on condition of anonymity said it’s more likely some seasonal workers would be laid off, adding anticipated budget gaps could also be resolved by delaying or cutting spending on other park projects.

The official also said the city has a “bad” habit of commissioning renderings for park projects “it knows it’ll never be able to fully fund” just to grab a quick headline “and boost the mayor’s popularity.”

Parks Department spokesman Phil Abramson said it sometimes pays for the city to develop project designs before securing full funding so construction can smoothly start “when additional funds are available.” He also said the administration “remains committed to its historic investments in the park system,” which included a record $552 million in capital project spending last fiscal year.

The mayor through PlaNYC also pledged to convert 290 schoolyards into community parks so every New Yorker would be within a 10-minute walk of a playground by 2030. But this plan was also hit hard by cuts, the council study says.

Of the 221 yet to be built, funding has been slashed by $13.3 million, from $77.2 million to $63.9 million.

Geoffrey Croft of the watchdog group New York City Park Advocates called the department’s capital program a “disaster, especially PlaNYC.” He said the city continues “to make promises it knows it can’t deliver on some projects while spending like drunken sailors on others.”

Among the non-PlaNYC projects hit hard by the fiscal cuts are a few in Williamsburg and Greenpoint in Brooklyn that were promised to residents by city officials to help push through a controversial rezoning plan in 2005 which brought high-rise housing to the waterfront.

Funding for the planned $30 million Bushwick Inlet Park on the Williamsburg-Greenpoint border has been pushed back to at least 2013, leaving it in jeopardy, the council study says. Another project to build a soccer field on Commercial Street in Greenpoint has seen funding gutted from $14 million to $1 million.

In all capital funding for Williamsburg-Greenpoint projects has been cut to $112.1 million, down from $169.1 million in January, officials said.